From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 72DB4C433FE for ; Thu, 29 Sep 2022 21:30:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229627AbiI2VaA (ORCPT ); Thu, 29 Sep 2022 17:30:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56270 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229799AbiI2V37 (ORCPT ); Thu, 29 Sep 2022 17:29:59 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 725CE36417; Thu, 29 Sep 2022 14:29:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=rXAbzFGK0jU8HKQfVHTw7kWBB/3401FxZQXUj1ewiAA=; b=hlF6332JfLej9LJRLWg/snSc7p povbjSrA68GNyAFUkAonIT7X7npZNcZ0BNDosog4Gu0CYQZIlS117+wKaJ4/gxDO5sx34kHq6sKsX ZEf9zxvjRa4o1S9McfNVwDp5/PSR2iXwNCHky24BbCcoNodPlE6i2dnn84jEbGI4Wz9Y6QDaJvGOH 3oZlCj9iCM2Y/E8AbtiHIOVqFLkVO7CtPQl6JaHnS/+EO3wLca8mtDF12zuOyZmey76a86jr35m7x HIX2+s5ewd7KHxV+8JJccLfh7lpWBypdM/4G9k89SlGf3xJIUh0a9rInjPzCE0HWFjdincdFUt8Km szj0UOFw==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1oe16R-00Dcok-Aw; Thu, 29 Sep 2022 21:29:55 +0000 Date: Thu, 29 Sep 2022 22:29:55 +0100 From: Matthew Wilcox To: "Darrick J. Wong" Cc: linux-fsdevel , xfs Subject: Re: [PATCH] iomap: fix memory corruption when recording errors during writeback Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org On Thu, Sep 29, 2022 at 02:27:17PM -0700, Darrick J. Wong wrote: > On Thu, Sep 29, 2022 at 08:33:06PM +0100, Matthew Wilcox wrote: > > On Thu, Sep 29, 2022 at 11:44:49AM -0700, Darrick J. Wong wrote: > > > Fixes: e735c0079465 ("iomap: Convert iomap_add_to_ioend() to take a folio") > > > Probably-Fixes: 598ecfbaa742 ("iomap: lift the xfs writeback code to iomap") > > > > I think this is a misuse of Fixes. As I understand it, Fixes: is "Here's > > the commit that introduced the bug", not "This is the most recent change > > after which this patch will still apply". e735c0079465 only changed > > s/page/folio/ in this line of code, so clearly didn't introduce the bug. > > > > Any kernel containing 598ecfbaa742 has this same bug, so that should be > > the Fixes: line. As you say though, 598ecfbaa742 merely moved the code > > from xfs_writepage_map(). bfce7d2e2d5e moved it from xfs_do_writepage(), > > but 150d5be09ce4 introduced it. Six years ago! Good find. So how about: > > > > Fixes: 150d5be09ce4 ("xfs: remove xfs_cancel_ioend") > > Sounds fine to me, though if I hear complaints from AUTOSEL about how > the patch does not directly apply to old kernels, I'll forward them to > you, because that's what I do now to avoid getting even /more/ email. Well, autosel is right to complain ... there's a fix which doesn't apply magically to every still-supported kernel containing the bug. I'm happy to own backporting this one as far as necessary. > > Also, > > > > Reviewed-by: Matthew Wilcox (Oracle) > > However, thank you for the quick review. :) > > --D > > > > Signed-off-by: Darrick J. Wong > > > --- > > > fs/iomap/buffered-io.c | 2 +- > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c > > > index ca5c62901541..77d59c159248 100644 > > > --- a/fs/iomap/buffered-io.c > > > +++ b/fs/iomap/buffered-io.c > > > @@ -1421,7 +1421,7 @@ iomap_writepage_map(struct iomap_writepage_ctx *wpc, > > > if (!count) > > > folio_end_writeback(folio); > > > done: > > > - mapping_set_error(folio->mapping, error); > > > + mapping_set_error(inode->i_mapping, error); > > > return error; > > > } > > >